A theoretical study of the interaction between DNA/RNA and the noble metal atoms of gold and silver - Ground-state properties

摘要

Here, we present results from a study of DNA/RNA bases interacting with goldand silver atoms at three charge states: neutral, cationic, and anionic. Usinga real-space DFT methodology, we describe the nature of the stability, bonding,and electronic properties in each hybrid metal. After studying five isolatednucleobases, including the effect of pairing respective DNA-Watson-Crick basepairs and the sugar-backbone by studying the nucleotide guanine monophosphate,we discerned that the energetic ordering of isomers, for a given base-metalcombination, follows simple electrostatic rules, and therefore can beextrapolated to more complex structures. When considering the electronicproperties of the ground-state structure in every combination of base andcharge, we derived several general features. First, allthough the metallocalizes almost all of the extra charge in the anionic system, a donation ofcharge is shared almost equally by the metal and nucleobase in the cationicsystem. Second, the frontier orbitals of the anionic and cationic system aredifferent, with the latter tending to have more effects from the pairing andinclusion of the backbone. Finally, the electronic gap varies greatly among allof the considered structures and is particularly sensitive to the backboneparticipation in the bonding. Thus, it could be further used as a fingerprintwhen searching Au/Ag-DNA hybrid atomic